Pair Of Straight Lines Question 16
Question: If the equation $ 2x^{2}-2hxy+2y^{2}=0 $ represents two coincident straight lines passing through the origin, then $ h= $
Options:
A) $ \pm 6 $
B) $ \sqrt{6} $
C) $ -\sqrt{6} $
D) $ \pm 2 $
Show Answer
Answer:
Correct Answer: D
Solution:
If it represents two coincident straight lines, then the condition $ h^{2}-ab=0 $ should apply as angle between them would be zero. Hence $ h^{2}-4=0 $ or $ h=\pm 2 $ .
BETA
